The aim of this project is the establishment of methods and information necessary to elucidate the stereochemistry of intermolecular interactions. To this end, a rationale is presented which applies the principles of classical stereochemistry to the problems of intermolecular orientation in aggregates such as complexes, ion pairs, micelles (normal and reversed), monolayers, and membranes. Enantiomeric and diasteriomeric interactions will be studied for carefully chosen chiral substrates by a battery of thermodynamic, kinetic, and spectroscopic methods. The project is fundamentally problem oriented and accordingly would integrate methods from a variety of areas in stereo-organic, physical, biological and interfacial chemistry to achieve our ends. Since the methodology provides absolute assignments to relate differences in molecular structure to reactivity, the results should provide rigorous information for many systems used in our study. In addition to the basic value of this research to many health-related areas we specify examples where the understanding of stereospecific physiological interactions of pheromones, prostaglandins, and amphetamines could be directly affected. Criteria for the choice of experimental compounds and methods are given and the results of preliminary studies demonstrate the possibility of a number of the proposed methods. A chiral surfactant of known configuration has been synthesized which exemplifies the stereochemical and physical criteria for approaching the problem. The material is claimed to be active against arteriosclerosis in accordance with our concern for biomedical relevance.